"The Barracks which you have listed in the Dun Laoghaire Harbour area is nothing more than a recruitment centre & has no military capabilities at all. By that I mean, there are no military weaponry or equipment stored there. Likewise because it is simply a reserve office for recruitment in the immediate area it is not intended for use as a defended position so it has no fences, metal doors etc.

Likewise in the Barracks in Rathmines, there is absolutly no chance of a bunch of unarmed civilians carrying crowbars breaking in to the weapon storage areas. The rifles & machine guns you've mentioned above will either be in cages, behind heavy metal doors or out with the soldiers on duty, who may or may not be infected. Thus the main chance of getting weapons are from already infected soldiers in the city centre area, who have left them behind.

In relation to vehicles I would recommend large lorries, either the military troop carrying ones or the ones used to carry gravel etc. There is an abundance of these in Dublin & the surrounding areas. Because they are high off the ground & have large wheels they should be useful for driving through large crowds of infected & have an ample amount of space for storage of supplies & survivors.

In general I'd be against going to Dublin port because it is so close to the city centre, DunLaoghaire is in a less populated area, so might be a safer option. Just a few ideas! Other than that I did enjoy the general plan you've laid out :]
-Chris"